String callback = (HttpUtil.isJSONP(servletRequest) &&
ContentTypes.OUTPUT_JSON_CONTENT_TYPE.equals(responseConverter.getContentType())) ?
servletRequest.getParameter("callback") : null;
if (callback != null) writer.write(callback + '(');
writer.write(responseConverter.convertToString(response));
if (callback != null) writer.write(");\n");
} else {
sendError(servletResponse, responseItem);
}
}